Apparatus and method for erecting containers

ABSTRACT

Apparatus and method wherein a three-piece container is erected by carrying separate end panels with a mandrel into contact with a main body blank and moving the blank and end panels with the mandrel through a container-erecting station where end panelengaging flaps along opposite end edges of the bottom and side walls of the blank are brought into contact with the outer surface of the end panels. Corner-strengthening flaps are also provided along opposite side edges of the end panels, and means are provided adjacent the path of mandrel travel to fold the latter flaps simultaneously inwardly prior to contact of the end panels with the body blank to permit such end panel flaps to engage the inner surface of the side walls of the container. Means are provided to permit the end panels to be moved in two stages by the mandrel from their initial positioning station first to an initial rest position, then to their finally erected position in the container.

[ 1 May 2, 1972 [54] APPARATUS AND METHOD FOR ERECTING CONTAINERS [72] Inventors: Paul Wasyluka; Clinton E. Zolman, both of St Louis, Mo.

Crown Zellerbach Corporation, San Francisco, Calif.

[22] Filed: Mar. 30, 1970 [21] Appl. No.: 23,654

[73] Assignee:

[52] U.S. Cl. ..93/5l M, 93/36 M, 93/39 R,

FOREIGN PATENTS OR APPLICATIONS 799,583 8/1958 Great Britain ..93/59 PL Primary ExaminerWayne A. Morse, Jr. AttorneyCorwin R. Horton and John O. Reep [57] ABSTRACT Apparatus and method wherein a three-piece container is erected by carrying separate end panels with a mandrel into contact with a main body blank and moving the blank and end panels with the mandrel through a container-erecting station where end panel-engaging flaps along opposite end edges of the bottom and side walls of the blank are brought into contact with the outer surface of the end panels. Cornerstrengthening flaps are also provided along opposite side edges of the end panels, and means are provided adjacent the path of mandrel travel to fold the latter fiaps simultaneously inwardly prior to contact of the end panels with the body blank to permit such end panel flaps to engage the inner surface of the side walls of the container. Means are provided to permit the end panels to be moved in two stages by the mandrel from their initial positioning station first to an initial rest position, then to their finally erected position in the container.

10 Claims, 6 Drawing Figures Patented May 2, 1972 3,659,505

4 Sheets-Shae: 1

PAUL WASYLUKA I CLINTON E. ZOLMAN INVENTORS.

Patented May 2, 1972 4 Sheets-Sheet 2 PAUL WASYLUKA v INVENTORS ATTY.

Patented May 2, 1972 3,559,505

4 Sheets-Sheet 3 BY W212.

Patented May 2, 1972 3,659,505

f Zi-igg; 127, 2? lza w F IG 6 FIG. 5

PAUL WASYLUKA CLINTON E. ZOLMAN INVENTORS APPARATUS AND METHOD FOR ERECTING CONTAINERS BACKGROUND OF THE INVENTION The present invention relates to apparatus and methods for erecting containers and, more particularly, to erecting containers from three-piece blanks having a main body blank and separate end panels.

There is known apparatus for erecting containers from three-piece blanks as disclosed, for example, in such prior patents as U.S. Pat. Nos. 3,342,116 and 3,416,789 Roesner et al. In general, the apparatus disclosed in the patents just mentioned are operable to erect a container from a three-piece blank wherein a mandrel carries separate end panels with it into contact with a main body blank located above a bodyerecting die cavity and, when the end panels and body blank are moved into the cavity, the blank is erected about the end panels. Flaps along opposite edges of the bottom and side walls of the body blank are engaged with and adhered to the outer surface of the end panels.

It is desirable, however, to have an apparatus and method which is capable of erecting a container having additional internal flaps at the corners to strengthen the comers of such three-piece containers and increase the stacking strength thereof.

SUMMARY It is therefore an object of the present invention to provide an apparatus and method capable of erecting a three-piece container having both outer and inner flaps adjacent the corners thereof to increase the stacking strength of such containers.

In accordance with one aspect of the present invention, a main body blank is positioned at a blank-receiving station which is between a container-erecting station and a reciprocably-mounted mandrel. The plane of the blank is perpendicular to the longitudinal direction of movement of the mandrel, and the body blank includes a bottom wall, side walls and flaps along opposite side edges of the bottom and side walls. A pair of separate end panels also has flaps along opposite side edges thereof, and the end panels are positioned against opposite sides of the mandrel at a positioning station which is on the opposite side of the blank-receiving station from the container-erecting station. Means are provided on the mandrel to carry the end panels therewith during movementtoward the body blank to contact the end panels with the body blank. Before such contact of the end panels with the body blank is made, however, the end panel flaps are folded inwardly by plow means located adjacent the path of travel of the mandrel so that such flaps will engage the inner surfaces of the body side walls when they are erected. Then the mandrel advances the end panels and main body blank through the container-erecting station where the side walls are erected and the body blank flaps are folded into contact with the outer surface of the end panels. The inner surface of the body blank flaps and the inner surface of the body blank which engages the end panel flaps has suitable adhesive applied thereto prior to erecting the container to secure the container in its erected position.

In accordance with another aspect, the end panels are movedin two stages from the end panel-positioning station to the finally erected position of the container. A first stroke of the mandrel carries a first pair of end panels to an initial rest position where the end panel flaps are folded. A second stroke of the mandrel carries a second pair of end panels to the initial rest position while the first pair of end panels are moved by the second mandrel stroke into contact with the body blank and through the container-erecting station. Such two-stage operation reduces the length of the mandrel stroke which otherwise would be required.

BRIEF DESCRIPTION OF THE DRAWING The invention will be better understood from the following description taken in connection with the accompanying drawings in which:

FIG. 1 is a partially diagrammatic side sectional view showing an interrelationship of parts of the apparatus with the mandrel in outer position;

FIG. 2 is a partially diagrammatic perspective view showing the apparatus and the interrelationship of various stations with the mandrel in outer position;

FIG. 3 is a plan view of the three-piece container blank to be erected by the apparatus of the present invention;

FIG. 4 is a partially diagrammatic perspective view similar to FIG. 2 but with certain parts removed and illustrating the mandrel at the very beginning of inward movement;

FIG. 5 is a view similar to FIG. 4 but showing the mandrel at its inner position; and

FIG. 6 is a sectional view illustrating the end panel-restraining means at the rest position.

GENERAL DESCRIPTION It will be helpful, in order to more fully understand the apparatus and method involved in the present invention, to first view an illustration of a three-piece container adapted to be erected according to this invention. With reference FIG. 3 there is illustrated a blank including a main body blank 10 and separate end panels 11 and 12, all of which may be formed from cardboard or other suitable material conventionally used for containers.

The blank 10 is generally rectangular and includes a bottom wall panel 13. Side wall panels 14 and 15 are hingedly associated with the bottom wall panels along transverse score lines 16 and 17. Longitudinal score lines 18 and 19 define flaps 20 and 21 hingedly associated with opposite side edges of the bottom wall panel, and such score lines also define flaps 22, 23, 24 and 25 hingedly associated with opposite side edges of the side panels. Notches 26 are cut into the flaps at the intersections of score lines 18 and 19. The separate end panels 11 and 12 are also each generally rectangular in shape. Score lines 27 and 28 define end panel flaps 29 and 30 which are hingedly connected to the end panel 11 along opposite side edges thereof, and score lines 31-and 32 define end panel flaps 33 and 34 which are hingedly connected to the end panel 12 along opposite side edges thereof. End panel 11 has top 35 and bottom 36 edges; and end panel 12 also has top 37 and bottom 38 edges. The three-piece container blank thus includes blank 10 as a first piece and end panels 11 and 12 as second and third pieces, and the relationship of the pieces in the erected container can best be seen at FIGS. 4 and 5.

In erecting a container from the blank just described, a main body blank 10 is positioned at a body blank-receiving station 40 where one edge of the blank is supported on a suitable supporting surface 41 (FIG. 1). A container-erecting station 42 is located on one side of the blank-receiving station 40, and a reciprocably-mounted mandrel 44 is located on the other side of the station 40 when the mandrel is in its extreme outer position.

While sequential blanks 10 could be individually positioned by hand at the station 40, it will be desirable in most instances to provide means for automatically feeding such blanks at predetermined timed intervals to the station 40; and, in the instance of providing such automatic feed means, reference should be made to FIG. 1 which illustrates a stack of such blanks 10 disposed in vertical planes above the station 40. The notches 26 in the blanks provide convenient means to receive surfaces on vertically inclined support members 45 located on opposite sides of the stack (only one of which is depicted in phan wm outline). The innermost blank 10 in the stack is free to be moved downwardly but it is biased against the next adjacent blank by means of an arm 46 which bears against one surface of the innermost blank.

One end of the arm 46 has pin-like projections 47 which penetrate very slightly into the blank. The arm is pivotally secured to a connecting link 48 about pivot point 49, and a spring 50 connects the other end of the arm to such link to continually urge the pointed end 47 into contact with a blank 10. The end of the link 48 remote from pivot point 49 is secured to a support rod 51 for rotation therewith. Thus, counterclockwise rotation of the rod 51 about its axis causes the arm 46 to also move downwardly and carry a blank with it because of the slight piercing action of the pins 47.

Rotation of the rod 51 is accomplished through the medium of rods 52 and 53 and links 54, 55 and 56, all of which derive their motion from a cam 57 secured to an axle 58 of a main drive source. The axle 58 is continuously driven in the direction of the arrow causing oscillation of link 56 about pivot point 59 because of a cam follower 60 at one end of link 56 engaging the cam 57. Contact of cam follower 60 with cam 57 is assured by virtue of a coil spring 61 having one end secured to a bracket 62 and having the other end fixedly secured to the main frame structure of the machine. Oscillation of the link 56 also imparts oscillation to rod 53 which has one end thereof pivotally secured to the link 56 on the opposite side of the pivot point 59 from the cam follower 60. The other end of rod 53 is pivotally secured to link 55 which is mounted for pivoting about axis 63. Rod 52 also has one end pivotally secured to link 55 so that motion of the link 55 is transmitted to rod 52. The other end of rod 52 is pivotally secured to link 54, and the opposite end of this link 54 is fixedly secured to rod 51 so that oscillation of the link 54 is also transmitted to the rod 51.

The downward'movement of arm 46 need only be sufficient to bring the leading edge of inner blank 10 into the nip of a pair of continuously driven, rubber-covered transfer rolls 64 and 65 which engage the blank 10 to move it downwardly to the station 40.

It is convenient to apply adhesive to the appropriate blank surfaces along lines 66 and 67 (FIG. 3) while the blank is being moved downwardly, and any suitable adhesive applicator 70 may be used for this purpose. Since the applicator forms no part of the present invention, it has not been disclosed in detail but applicators such as those disclosed in U.S. Pat. No. 3,l52,923 or in the aforementioned Roesner et al. patents may be used. The type of adhesive used will depend, in part, on the speed at which the machine is operated. If blanks are moved rapidly through the container-erecting station it will be desirable to use a fast-setting adhesive of the so-called hot-melt type, but cold adhesive could be used if the operation is slow enough. It may be desirable to utilize lines of both fast-setting and slower setting adhesive.

After the blank 10 has arrived at the station 40, it is in position to have mandrel 44 carry a pair of end panels 11 and 12 into contact with the bottom panel 13 just inwardly of score lines 18 and 19 and then move the blank 10 and end panels 1 1 and 12 through the container-erecting station 42 to erect the container, all in a manner to be described later in greater detail.

The mandrel 44 includes a leading end 71 and a trailing end 72. Structurally, the mandrel is made up of generally L-shaped corner elements 73, 74, 75 and 76 interconnected in substantially rectangular cross-sectional relationship by vertical-connecting elements 77 and horizontal-connecting elements 78. Vertically extending legs 73a, 74a, 75a and 76a on the comer elements provide opposed side surfaces for the mandrel, and horizontally extending legs 73b and 74b provide a top surface. Horizontally extending legs 75b and 76b provide a bottom surface as seen at FIG. 2, and bottom legs 75b and 76b are slideably received in generally U-shaped main horizontal frame members 79 and 80 extending the length of the mandrel, and the frame members are in turn suitably supported from the ground by vertical frame members 81 and 82.

End panel-carrying means are provided on the mandrel 44 for carrying end panels 11 and 12, which have been positioned against the opposed side surface of the mandrel, with the mandrel into contact with the main body blank 10 and then advancing the assembly through the container-erecting station 42. Such end panel-carrying means are preferably in the form of front shoulder members 83, 84, 85 and 86 and rear shoulder members 93, 94, and 96. All of the aforementioned shoulder members may be of substantially identical construction except that the from shoulder members may be shorter than the rear shoulder members. The shoulders are suitably secured to the outer side surfaces of comer elements 73, 74, 75 and 76. The front shoulder members may, for example, be about 4% inches long, and the rear shoulder members may be about 10% inches long. To provide for adjustability of the position of the shoulder members along the length of the mandrel, the shoulder members can be secured to the mandrel by a nut and bolt arrangement wherein the bolts have heads received in recesses in the shoulders and pass through slots in the mandrel for securance thereto. Considering the shape of shoulder member 96 (FIG. 5), it has a leading edge 96a which is pointed to facilitate engagement with the end panel, and a trailing edge 96b which is beveled. The other shoulder members have similar leading and trailing edge shapes identified by appropriate subscripts a and b."

The front shoulder members comprise a first group 83-86 which are secured respectively to the legs 73a-76a of the mandrel. The leading pointed edge of each of the front shoulder members in this first group is spaced from the leading end 71 of the mandrel 44 a distance substantially equal to the distance between top and bottom edges 35 and 36, and 37 and 38 of the end panels 11 and 12, which, for example, may be 9% inches. The rear shoulder members comprise a second group 93-96 which are also secured respectively to the legs 73a-76 of the mandrel, and the leading pointed edge of each of the shoulder members of second group is spaced from the trailing edges of the shoulder in the first group which is on a common comer element a distance greater than the distance between top and bottom edges of the end panels 11 and 12. For example, the distance between leading edge 96a of shoulder 96 and trailing edge 86b of shoulder 86 may be 19% inches. The rear shoulder members are all spaced an equal distance from the leading end of the mandrel. The thickness of the shoulder members are just slightly less than the thickness of the end panels 11 and 12.

To permit end panels to be positioned against opposite side surfaces of the mandrel, end panel-positioning stations 97 and 98 are located adjacent opposite sides of .the mandrel and spaced from the body blank-receiving station 40. When the mandrel is in extreme outer position (FIGS. 1 and 2) the bottom edges 35 and 38 of end panels at the station 97 and 98 are spaced 15% inches from the leading end of the mandrel and the leading end of the mandrel is spaced l-2 inches from the front surface of blank 10 at station 41. While, as with the body blanks 10, positioning of the end panels 11 and 12 could be accomplished manually, it will be desirable to supply end panels in pairs from supply hoppers 99 and 100.

The end panel supply hopper 99 includes a pair of inclined substantially L-shaped members which together provide a supporting bottom wall 103 and side walls 104 and 105 for the supply hopper to receive a plurality of end panels stacked in the manner illustrated at FIG. 4. Supply hopper is similarly constructed and includes bottom wall 106 and side walls 107 and 108. The inner edge of the supply hoppers 99 and 100 terminate just short of the outward reach of the shoulders 93-96 on the mandrel 44 so that the hoppers will not interfere with reciprocating motion of the mandrel. .An L- shaped bracket 109 is positioned adjacent the upper inner edge of each of the walls 104 and 107 on the supply hoppers. This bracket extends slightly inwardly of the inner edge of the hoppers but still does not interfere with the mandrel because, as regards bracket 109, it is in a location between the corner elements 74 and 76 of the mandrel. A similar bracket is positioned in wall 104 of hopper 99 between corner elements 73 and 75. The brackets are to restrain the end panels from following the mandrel when it is being removed from the container-erecting station 42.

The weight of the end panels and the inclination of the hoppers aids in assuring that when a first pair of end panels is removed from the hoppers a second pair gravitates to the position previously occupied by the first pair. If desired, weighted follower members can be positioned behind the outermost end panel in each stack to gain further assurance that the sequential forward movement of the end panels takes place. The particular type of end panel supply hoppers is, however, not critical and end panel feed means similar to that disclosed in US. Pat. No. 3,342,116 could also be used.

As previously mentioned, one important aspect of the present invention resides in the provision of plow means which are located between the end panel-positioning stations 97 and 98 and the body blank-receiving station 40 and are positioned adjacent the path of travel of the mandrel for turning the end panel flaps 29, 30, 33 and 34 at substantially right angles to the end panels 11 and 12 prior to engaging the end panels with the main body blank. As illustrated at FIGS. 2 and 5 the plow means comprises generally right triangular plates 110-113 which are secured at one end by brackets 114-117 to main vertical frame members 118 and 119. Plow means 111 and 112 are located above respective mandrel corner elements 73 and 74 a distance just slightly greater than the thickness of end panel flaps 29 and 33. The sloping surfaces of the plows open outwardly toward the trailing end of a mandrel so that when the flaps 29 and 33 of end panel are brought into contact with the plows 111 and 112 during movement of the panels 11 and 12 with the mandrel 44, the plows function to turn the end panel flaps inwardly against the upper surfaces of the mandrel. The substantially identical bottom plow members 1 l0 and 113 are positioned and act in a similar manner to turn end panel flaps 30 and 34 inwardly against the bottom surface of the mandrel.

As heretofore mentioned, it is desirable to feed the end panels 11 and 12 in two stages from the end panel-positioning stations 97 and 98 to the container-erecting station 42 in order to reduce the length of the mandrel stroke which otherwise may be required. After the first pair of end panels have been advanced to their intermediate rest position, it is desirable to provide means for restraining this first pair of end panels from returning rearwardly with the mandrel during completion of its first stroke. The preferred end panel-restraining means just referred to is illustrated most clearly at FIGS. 2 and 6 where it is seen that the restraining means comprises a pair of substantially identical movable or floating plates 120 and 121 positioned respectively adjacent opposite sides of the mandrel between the panel-positioning stations 97 and 98 and the blank-receiving station 40. Considering plate 121, the leading end has a beveled surface 122 which terminates in a point 123 spaced slightly outwardly of the outer surface of end panel 11 when the end panel is positioned against the side 74a and 76a of the mandrel. The leading edge 35 of the end panel, however, strikes the sloping surface 122 during forward movement of the mandrel 44 to urge the floating plate 121 outwardly of the end panel 11 until the trailing edge 36 of the end panel clears shoulder 124 on the inner surface of the floating plate 121. Then the plate 121 returns to a position illustrated at FIG. 6 where the shoulder 121 restrains the end panel 11 from following the mandrel 44 during the return portion of the mandrel stroke. The plate 120 acts in a similar manner to restrain panel 12 and the plates 120 and 121 are suitably attached to main vertical frame members 118 and 119 through the medium of L-shaped brackets 125 and 126.

Again referring to FIG. 6, one leg of the bracket 125 is secured to the frame 118 and the other leg has spaced apertures 127, 128 and 129. A pair of screws 130 and 131 are slideably received through two of the apertures, the screws being attached to the plate member 121. A coil spring 132 around a center post 133 biases the plate 121 toward the mandrel.

As hereinbefore stated, the container-erecting station 42 is located on the opposite side of the blank-receiving station 40 from the mandrel 44 when the mandrel is in its extreme outer position. The station 42 includes elements to erect the side walls 14 and 15 of the container when the container is moved past such elements, and also includes elements to turn the flaps 22, 23, 24 and 25 into contact with the outer surfaces of the end panels 11 and 12. There is also preferably provided means to engage a trailing edge of the erected container to gain assurance that the erected container will be stripped from the mandrel during a return stroke of the mandrel.

Side wall-erecting elements comprise four plates 134, 135, 136 and 137, two of which extend slightly below the upper and lower levels respectively of the mandrels upper and lower surfaces. The ends of the plates 134-137 most immediately adjacent the station 40 are flared outwardly. The plates 134-137 thus define, in essence, a cavity for receiving the mandrel and erecting the side walls of the container about the mandrel.

Initial side wall flap-bending members 138-141 are located in the path of travel of flaps 22-25 to turn the flaps against the end panels 11 and 12, and secondary members 142-145, each in the form of a series of rubber-covered rollers, are properly positioned to further insure engagement of the flaps 22-25 with the end panels while adhesive applied to the contacting surfaces is given a chance to set.

Rubber-covered rollers 146 and 147 are properly positioned in the erecting station 42 to turn bottom wall flaps 20 and 21 into engagement with' the outer surface of the end panels.

Means to assure that an erected container will be stripped from the mandrel during return movement thereof is in the form of a pivotable plate 157 suitably secured to an appropriate frame member. One end has a shoulder 158 along the bottom surface thereof in position to engage the top edge of side wall 14 in the erected container. Thus, movement of the container into station 42 raises plate 157 just enough to allow the container to clear the plate but once the container is past shoulder 158, the plate moves so that the shoulder will engage the top edge of wall 14 if the container tries to follow the mandrel in its return stroke.

While any suitable means may be utilized for accomplishing reciprocation of the mandrel 44, one suitable means can be understood by referring to FIG. 1. A gear plate 148 is secured to the axle 58 and the gear plate may be continuously driven in the direction of the arrow. A groove 149 is cut in the plate and this groove forms a cam trackway for cam follower 150 secured to one end of link 151. The other end of link 151 is fixedly secured to a transverse rod 152 so that movement of the link causes oscillation of the rod 152, such rod being journaled for rotation about its axis through the medium of suitable journals supported from the main frame at the end of the rod 152. A connecting arm 153 has one end connected to rod 152 so that oscillating movement of the rod is transmitted to arm 153. The other end of the connecting arm is pivotally attached at 154 to one end of a drive arm 155, the other end of the drive arm 155 being pivotally secured to a fixed transverse bar 156 secured to opposite sides of the mandrel near the leading end thereof. One complete revolution of the gear plate 148 therefore drives the mandrel from its extreme outer position of FIG. 1 to an extreme inner position within the contamer-erecting cavity and back to the extreme outer position. The distance the mandrel travels between outer and inner positions is about 25 inches.

The cam trackway 149 can be suitably dimensioned to cause a dwell time at the extreme outer position of sufficient length to permit cam 57 to advance a body blank 10 to the station 40 during such dwell time.

So that the illustration in the figures of the drawing are more easily understood, it has not been deemed necessary to specifically illustrate the supporting framework for all of the elements, such as the end panel supply hoppers 99 and 100, and the elements in the container-erecting station. It will be readily apparent to one skilled in the art that all of such elements may readily be attached to any suitable main or auxiliary frame member providing the proper relationship as regards proper positioning of the parts is accomplished.

It is important to note (see FIG. 1) that when mandrel is in extreme outer position, the first (front) group of shoulder members 83-86 have their leading or pointed edges between the top edges 36 and 37 of the end panels 11 and 12 and the blank-receiving station 40 and the pointed edges of the second group of shoulder members 93-96 are located behind such top edges.

To summarize the operation, and with reference to FIGS. 1 and 4, a first complete stroke of the mandrel 44 is utilized to advance a first pair of end panels 11 and 12 from the panel positioning-stations 97 and 98 to a first rest position beneath flap-folding plows 110-113. The longitudinal position of second shoulders 93-96 on the mandrel and the position of the stations 97 and 98 are so selected relative to the length of the mandrel s stroke to assure that the end panels properly arrive at the first stage rest position. Then a body blank 10 is moved to station 40 while the mandrel 44 is in its outer position after the first stroke, and this is the relationship illustrated at FIG. 1. Then a second stroke of the mandrel causes the first shoulder members 83-86 to move the first end panels 11a and 12a into contact with the body blank and through the erecting station while a second group of end panels 11b and 12b is moved to the rest position previously occupied by the first group of end panels. Each subsequent stroke of the mandrel similarly erects a container while moving end panels to a ready position immediately in front of the blank-receiving station 40.

The beveled edges at the rear end of the shoulder members 83-86 are effective to permit the shoulder members to easily move past end panels at the rest station during a return stroke of the mandrel, and beveled edges on shoulder members 93-96 similarly permit such shoulders to move past end panels at stations 97 and 98 during a return stroke of the mandrel.

While a preferred embodiment of the invention has been illustrated and described, various other embodiments and modifications thereof will be apparent to those skilled in the art, but will fall within the spirit and scope of invention as defined in the following claims.

We claim:

1. In an apparatus for erecting a container from a blank including a main body blank and separate end panels; said main body blank having a bottom wall, opposed side walls and end panel-engaging flaps along opposite end edges of the bottom wall and side walls; said apparatus including a frame; a con tainer-erecting station including container-erecting elements mounted on said frame; a main body blank-receiving station in front of the container-erecting station including means to support the body blank; a forming mandrel having leading and trailing ends, said mandrel being reciprocably mounted on said frame for longitudinal movement between an extreme outer position where the leading end of the mandrel is spaced on the opposite side of the body blank-receiving station from the container-erecting station to an inner position within the container-erecting station to move sequential body blanks from the panel-receiving station through the container-erecting station; an end panel-positioning station located adjacent opposite sides of said mandrel where end panels are received along opposite sides of the forming mandrel in advance of the main body blank-receiving station; means on the mandrel for carrying end panels with it through the main body blankreceiving station and container-erecting station; wherein said end panels include flaps along opposite side edges thereof; and wherein the improved apparatus comprises plow means located between the end panel-positioning station and the main body blank-receiving station and positioned adjacent the in ufaces interconnected in substantially rectangular, cross-sectional relationship to define a leading end which enters the container-erecting station and a trailing end, and wherein said end panel-carrying means comprises shoulder members secured to the outer side surfaces of said comer elements.

3. The apparatus as set forth in claim 2 wherein each corner element has first and second shoulder members secured thereto and longitudinally spaced apart from each other a distance greater than the depth of an end panel.

4. The apparatus as set forth in claim 1 wherein said end panel-carrying means comprises first and second shoulder members longitudinally spaced from each other and secured to opposite sides of said mandrel, said first shoulder members being located toward the leading end of the mandrel from the second shoulder members, said second shoulder members being so located by position on the mandrel relative to the end panel-positioning station, to carry a first pair of end panels from the end panel-positioning station to a rest position intermediate the latter station and the main body blank-receiving station by a first stroke of the mandrel and to carry a second pair of end panels to said rest position during a second stroke of the mandrel while said second stroke carries the first pair of end panels with the main body blank through the blank-erecting station.

5. The apparatus as set forth in claim 3 wherein said first shoulder members have front edges which are spaced from the leading end of the mandrel a distance substantially equal to the depth of an end panel.

6. The apparatus as set forth in claim 5 wherein the shoulder members have rear ends which are beveled.

7. The apparatus as set forth in claim 4 which further includes end panel-restraining means secured to the frame and located between said main body blank-receiving station and said end panel-positioning station for restraining the first pair of end panels at said rest position when said mandrel is returned during said first stroke from the inner to the outer position of the mandrel.

8. The apparatus as set forth in claim 7 wherein said restraining means comprises movable plates adjacent opposite sides of the mandrel and biased toward said mandrel, said plates each having a shoulder on the inner surface thereof for engaging the end panels at said rest position when said mandrel is moved from the inner to the outer position thereof.

9. The apparatus as set forth in claim 4 wherein the end panels have top and bottom edges located respectively toward the trailing and leading ends of the mandrel and extending Y substantially perpendicular to the direction of movement of the mandrel, and wherein said first shoulders each have a front edge which is located between the top edge of the end panels at the end panel-positioning station and the leading end of the mandrel when the mandrel is in an extreme outer position, and said second shoulders each have a front edge which is located toward the trailing end of the mandrel from the top edge of the end panels when the mandrel is in an extreme outer position.

10. In a method for erecting a container from a blank including a main body blank and separate end panels; said main body blank having a bottom wall, opposed side walls and end panel-engaging flaps along opposite end edges of the bottom wall and side walls, which method includes: positioning the main body blank at a blank-receiving station between a container-erecting station and a reciprocable mandrel; positioning a pair of separate end panels against opposite sides of the mandrel at an end panel-positioning station, and moving the mandrel and end panels into contact with the body blank and thence through the container-erecting station wherein the improvement comprises: providing end panel flaps hingedly attached along opposite side edges of the end panels and, during a first full stroke of the mandrehtuming said end panel flaps of a first pair of end panels inwardly at substantially right angles to the end panels while the first pair of end panels travels from the end panel-positioning station to a rest position between the latter station and the body blank-receiving station, and moving a second pair of end panels to said rest posi- 

1. In an apparatus for erecting a container from a blank including a main body blank and separate end panels; said main body blank having a bottom wall, opposed side walls and end panel-engaging flaps along opposite end edges of the bottom wall and side walls; said apparatus including a frame; a containererecting station including container-erecting elements mounted on said frame; a main body blank-receiving station in front of the container-erecting station including means to support the body blank; a forming mandrel having leading and trailing ends, said mandrel being reciprocably mounted on said frame for longitudinal movement between an extreme outer position where the leading end of the mandrel is spaced on the opposite side of the body blankreceiving station from the container-erecting station to an inner position within the container-erecting station to move sequential body blanks from the panel-receiving station through the container-erecting station; an end panel-positioning station located adjacent opposite sides of said mandrel where end panels are received along opposite sides of the forming mandrel in advance of the main body blank-receiving station; means on the mandrel for carrying end panels with it through the main body blank-receiving station and container-erecting station; wherein said end panels include flaps along opposite side edges thereof; and wherein the improved apparatus comprises plow means located between the end panel-positioning station and the main body blank-receiving station and positioned adjacent the path of travel of the mandrel for turning the end panel flaps at substantially right angles to the end panels prior to engaging the end panels with the main body blank and permitting engagement of the end panel flaps with interior surfaces of the side walls of the main body blank when the container and end panels are advanced through the container-erecting station.
 2. The apparatus as set forth in claim 1 wherein said mandrel includes spaced corner elements each including side surfaces interconnected in substantially rectangular, cross-sectional relationship to define a leading end which enters the container-erecting station and a trailing end, and wherein said end panel-carrying means comprises shoulder members secured to the outer side surfaces of said corner elements.
 3. The apparatus as set forth in claim 2 wherein each corner element has first and second shoulder members secured thereto and longitudinally spaced apart from each other a distance greater than the depth of an end panel.
 4. The apparatus as set forth in claim 1 wherein said end panel-carrying means comprises first and second shoulder members longitudinally spaced from each other and secured to opposite sides of said mandrel, said first shoulder members being located toward the leading end of the mandrel from the second shoulder members, said second shoulder members being so located by position on the mandrel relative to the end panel-positioning sTation, to carry a first pair of end panels from the end panel-positioning station to a rest position intermediate the latter station and the main body blank-receiving station by a first stroke of the mandrel and to carry a second pair of end panels to said rest position during a second stroke of the mandrel while said second stroke carries the first pair of end panels with the main body blank through the blank-erecting station.
 5. The apparatus as set forth in claim 3 wherein said first shoulder members have front edges which are spaced from the leading end of the mandrel a distance substantially equal to the depth of an end panel.
 6. The apparatus as set forth in claim 5 wherein the shoulder members have rear ends which are beveled.
 7. The apparatus as set forth in claim 4 which further includes end panel-restraining means secured to the frame and located between said main body blank-receiving station and said end panel-positioning station for restraining the first pair of end panels at said rest position when said mandrel is returned during said first stroke from the inner to the outer position of the mandrel.
 8. The apparatus as set forth in claim 7 wherein said restraining means comprises movable plates adjacent opposite sides of the mandrel and biased toward said mandrel, said plates each having a shoulder on the inner surface thereof for engaging the end panels at said rest position when said mandrel is moved from the inner to the outer position thereof.
 9. The apparatus as set forth in claim 4 wherein the end panels have top and bottom edges located respectively toward the trailing and leading ends of the mandrel and extending substantially perpendicular to the direction of movement of the mandrel, and wherein said first shoulders each have a front edge which is located between the top edge of the end panels at the end panel-positioning station and the leading end of the mandrel when the mandrel is in an extreme outer position, and said second shoulders each have a front edge which is located toward the trailing end of the mandrel from the top edge of the end panels when the mandrel is in an extreme outer position.
 10. In a method for erecting a container from a blank including a main body blank and separate end panels; said main body blank having a bottom wall, opposed side walls and end panel-engaging flaps along opposite end edges of the bottom wall and side walls, which method includes: positioning the main body blank at a blank-receiving station between a container-erecting station and a reciprocable mandrel; positioning a pair of separate end panels against opposite sides of the mandrel at an end panel-positioning station, and moving the mandrel and end panels into contact with the body blank and thence through the container-erecting station wherein the improvement comprises: providing end panel flaps hingedly attached along opposite side edges of the end panels and, during a first full stroke of the mandrel, turning said end panel flaps of a first pair of end panels inwardly at substantially right angles to the end panels while the first pair of end panels travels from the end panel-positioning station to a rest position between the latter station and the body blank-receiving station, and moving a second pair of end panels to said rest position during a second stroke of said mandrel while, during said second stroke, said first pair of end panels is moved with the body blank through the blank-erecting station to permit said end panel flaps to contact the inner surfaces of the side walls of the container when the container has been erected. 